JP2003-54341 A discloses a parking assisting apparatus comprising obstacle detecting means for detecting an obstacle near the vehicle; a vehicle motion calculating section configured to calculate the vehicle position and vehicle orientation in a two-dimensional plane based on steering angle and vehicle speed; and a target parking position determining section configured to detect a parking space based on the vehicle motion calculated by the vehicle motion calculating section and the relative positional relationship with respect to the detected obstacle and determine the target parking position.
By the way, a situation where the parking assist for the target parking position is impossible with such a type of parking assisting apparatus includes a situation where it is impossible to create a target track of the vehicle toward the target parking position from the current vehicle position (including a parking start position). If falling into such a situation, the parking assisting apparatus forces the driver to change the parking start position or the target parking position (or reset the parking process if the driver has started to move the vehicle for parking), bringing inconvenience to the driver. For this reason, it is of importance to make it difficult for the parking assisting apparatus to fall into such a situation, in terms of improving convenience of the parking assist.
One of the solutions to this problem includes a configuration in which the parking start position is set farther with respect to the target parking position enough to obtain a sufficient margin, and the vehicle is guided to the parking start position in a pre-parking stage. According to this configuration, since it becomes possible to calculate the target track of the vehicle toward the target parking position with a large margin, the situation where it becomes impossible to create the target track is not likely to occur even when the target parking position is subsequently changed to some extent.
However, in this configuration, since the parking start position has to be inefficiently set under a rigid constraint and the parking start position set in this way may largely depart from the ordinary parking start position in the case of not utilizing the parking assist, the improvement in convenience of the parking assist may be impaired.